OTC MENTHOL, EUCALYPTUS OIL AND CAMPHOR AS SINGLE NASAL DECONGESTANTS
OTC MENTHOL, EUCALYPTUS OIL AND CAMPHOR AS SINGLE NASAL DECONGESTANTS will not be included in the OTC nasal decongestant monograph, FDA OTC Division Director William Gilbertson, PharmD, noted in a Nov. 6 letter to Rich-Vicks. Gilbertson said that "at this time" a Rich-Vicks data submission "for camphor, eucalyptus oil, and menthol to be generally recognized as safe and effective as individual topical/inhalant nasal decongestant active ingredients, both in petrolatum applied to the chest and throat and in a hot steam vaporizer, are insufficient and these ingredients for these uses will not be included in the final monograph." Rich-Vicks submitted five studies to FDA in support of the effectiveness of the three ingredients as single active agents. Gilbertson said that after the agency's review of the data "although one study . . . does show some statistically significant evidence of the effectiveness of camphor, eucalyptus oil, and menthol . . . there are certain statistical problems with the data that make the results questionable." The remaining four studies, Gilbertson said, "are insufficient to demonstrate the effectiveness" of the three ingredients. Camphor, eucalyptus oil and menthol are three ingredients contained in Rich-Vicks' VapoRub and VapoSteam decongestant products. Gilbertson noted that "combination products containing these aromatic ingredients will be addressed at a future date in the combinations segment of the cough/cold rulemaking." In the one study that did show statistically significant evidence of efficacy, the three active ingredients were vaporized in steam and compared to a control of steam alone. A study population of 234 patients with acute upper respiratory infection was divided into four treatment groups. Using a rhinomanometer, baseline measurements of nasal airway resistance were made, with subsequent readings taken every 15 minutes in the first hour post treatment and twice in the second post treatment hour. "Each aromatic produced a median 10 percent or greater reduction of nasal congestion from both initial level and compared to steam alone at some point after treatment. Camphor and eucalyptus oil achieved both at all evaluation times, and menthol at four of the six evaluation times," Gilbertson noted. However, FDA concluded that the results of the study were not reliable because of three factors in the evaluation method: (1) "improper use of baseline values," (2) the questionable "assumption of homogeneity of variance in the analysis of variance," and (3) "improper use of statistical procedures to assess the treatment effects." Gilbertson said that "the Division believes that any reanalysis should include a nonparametric approach in determining treatment effects." While reiterating the questionable results of the study, Gilbertson said that even if it was evaluated properly the study "would only provide weak statistical evidence to support the reclassification of the individual active ingredients from Category III to Category I status. Another study to support the efficacy of these ingredients as topical/inhalant nasal decongestants would be necessary."
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